Heat and cold storage apparatus

ABSTRACT

Solar heat storage apparatus, invented by Thomason, includes a tank of water surrounded by a truckload of stones in a heat storage bin in the basement, U.S. Pat. No. 3,254,702 and others. Air circulating through the bin is warmed and circulated through the home to warm the home, or other building. 
     The present invention adds humidity to the air and also enhances heat transfer out of the storage bin and into the home by heat-of-vaporization. That permits use of heat from storage to a lower temperature level while making the home feel warmer. And, the solar heat collector obtains more free heat from the sun because it is operating at a lower temperature level and more efficiently. 
     Heat that normally goes up the chimney from an auxiliary heat source, such as a water heater or furnace, is used to assist home heating.

This application is a division of Ser. No. 480,752, filed June 19, 1974,now U.S. Pat. No. 4,029,082, June 14, 1977.

BACKGROUND

As the Energy Crisis was heaped on top of the Pollution Crisis the costsof electricity, oil, gas and coal skyrocketed. Attention turned to solarheating with the low-cost open-flow corrugated metal solar heatcollector (Thomason U.S. Pat. Nos. 3,145,707; 3,215,134, etc.). Thelow-cost Thomason heat storage bin, using free rain from the heavens andstones from the field, was widely studied and reported in manypublications (U.S. Pat. No. 3,254,702 and others). That basic storagebin, and modifications, permitted heat storage for the winter and wascompletely reversible for cold storage for the summer. And, it permitted"dry" storage to absorb excess moisture on hot muggy days (Thomason U.S.Pat. No. 3,812,903 and others).

Success of that storage apparatus included its ability to deliver heatout of storage down to a very low temperature level. Therefore most ofthe free stored solar heat could be used on cloudy days and nightsbefore expensive auxiliary heat from oil was required. By using moreheat out of storage the temperature was left lower. The water was coolerwhen it was pumped to the solar heat collector after the sun came out,or a bright cloudy day warmed the solar heat collector. Because thewater pumped to the collector was cooler it picked up more free heatfrom the sun, thereby making solar heat collection more efficient. Allof that lead to a very efficient system. It has low-cost components forcollecting heat, storing heat, cold and dryness, and recovering heat orcold from storage by automatic controls. The systems are known as the"Thomason Solaris Systems" and have been in continuous use since 1959.

BRIEF SUMMARY

The inventors are improving the basic "Solaris Systems" in many ways. Inthe present case, during the winter, they are adding humidity to the aircirculating through the storage bin to increase comfort in the home.And, they are increasing heat transfer from storage byheat-of-vaporization.

In its simple form, water is dispersed in the bin and it spreads topermit its evaporation into the air circulating therethrough. As thewater vaporizes it absorbs heat from the concrete floor, stones,concrete blocks, tank of water and so on, thereby leaving them cooler.The air, now humidified, is warmed further as it moves on through theheat storage bin. The warmed humidified air is then passed to the homeor other building to be heated. The humidified air feels warmer even ifits temperature is the same as drier air. Or, it feels just as warm evenif the temperature is actually lower. And, importantly, the water, etc.,in the storage bin, are left cooler because much of their heat has beenabsorbed by heat-of-vaporization and transferred into the home.

After yielding up heat, due to heat-of-vaporization around the tank (orfrom the tank in one embodiment), the water in the storage tank ispumped to the solar heat collector. That cooler water picks up moreBtu's of free heat from the sun than warmer water would have. Theresults are:

1. Higher efficiency of the system with more free heat from the sun;

2. A more comfortable home because the humidified air feels warmer thandry air.

3. The air in the home is not so dry and does not leave the occupantswith dry throats and noses.

In the present case the inventors are also reducing auxiliary heat costsby capturing and using heat that normally passes up the chimney from adomestic water heater, a furnace, or such.

IN THE DRAWING

FIG. 1 is a schematic diagram illustrating the invention;

FIG. 2 is an enlarged detail;

FIG. 3 is a modification;

FIG. 4 is another modification.

FIG. 1 diagramatically illustrates a feature of the invention wherein ahome or other building 1 has a solar heat collector 2 on a section ofthe roof facing the sun.

Heat storage bin 3 has therein a water tank 4 and stones, containers ofheat of fusion heat storage material or such 5. Water from tank 4 iscirculated through solar collector 2 by pump 6 and warm water isreturned to tank 4 in a manner described in numerous Thomason patents.

Water from tank 4 may flow out at 7 and through lines 8 and 9 to outlet10 in storage bin 3. Outlet 10 may, if desired, be a perforated pipe todistribute the water. Humidifier valve 11 may be controlled byhumidostat 12. A time switch 13 may be used if desired for purposesexplained hereinafter. Indeed, time switch 13 could be used for periodicoperation of valve 11 even without a humidostat. Or, the humidostatcould be used without a periodic time switch.

Warm water from tank 4 evaporates more readily and thereby; (1) addsmore moisture to the air, achieving a greater rate of humidification;and (2) transfers more heat out of storage into the air, andconsequently into the home or other space to be warmed and humidified.These desirable functions would not be obtained if cold "city" waterwere introduced directly to the stones.

Rainwater from the roof automatically fills tank 4 through gutter 14,automatic rainwater makeup and sediment trap 15 and fill line 16. Excessrainwater automatically overflows at 17. If the water in tank 4 drops tothe level of humidifier line 8 without adequate rain to restore thewater used from tank 4, then valve 18 may add water from the city watermain as needed for humidification purposes. Valve 18 may be a simplelow-cost automatic float controlled valve, similar to those used intoilets. It may be placed inside of trap 15, inside of tank 4, or may beconnected in other ways obvious to those skilled in the art.

Blower 19 circulates air from the upstairs area, preferably from thearea along the cold exterior walls as at 20, to the bottom of thestorage bin, up through the stones and around the warm tank of water andback out into the upstairs area as at 21.

The bottom of the storage bin may be slightly dish shaped as at 22. Thisis a simple matter of finishing the concrete floor with a little dip orwith turned-up edges. Then, when a limited amount of water is added atoutlet 10 it may spread out but not flow into adjacent basement areas.If an excess of water should accidentally discharge through outlet 10then an overflow drain 23 allows for automatic drainage. (The heatstorage bin occupies only 12%, leaving 88% of the basement spaceavailable for other uses in new solar house designs by the Thomasons.)

In FIG. 3 a modification uses a humidifier valve 11' to permit water toflow out from tank 4 through openings 11" into stones or such 5. Heat ofvaporization leaves the stones, etc. cooler. If further humidificationis desired lid 24 may be opened, by motor 25 for example, to permitmoisture to escape directly from the tank into the air being circulatedby blower 19. Either or both of these features yields heat transfer byheat-of-vaporization from the storage apparatus to the upstairs area.

FIG. 4 illustrates a feature that may be used to reduce heat losses upthe chimney. Domestic water heater (or furnace) 26 has a flue pipe 27with a branch 28 extending out into heat storage bin 3. Damper 29diverts the hot gases of combustion through branch 28 for the winter orbypasses branch 28 directly through section 30 to stack 31 during thehot summer.

If desired the domestic water heater 26 may be used to supply hot waterto a heating coil 33 in the heat storage bin. Flow of that water iscontrolled by valve 32. That provides auxiliary heat for long cloudyspells without use of an expensive furnace in a manner taught by theThomasons in application Ser. No. 398,323, filed Sept. 18, 1973. Colddomestic water enters at 34 and hot domestic water leaves at 35. (Ofcourse hot water for coil 33 could be provided by a regular furnace.)

OPERATION

When the tank of liquid and stones are warm, cold air from along thecold walls of the home, being heavy, drops to the bottom of the storagebin. That crowds the lighter warm air up through the warm bin, upthrough passages above and out into the living quarters. The result is alimited amount of absolutely free heat transfer by natural convectioncurrents. When added heat is needed, a thermostat, not shown, turnsblower 19 on to boost air circulation and heat transfer. (Only 1/6 HP isused in Thomason Solar House No. 3.) If additional heat is needed valve32 is opened by a second set of contacts on the thermostat to supplysupplementary heat, all controlled by a single thermostat.

When humidostat 12 calls for more moisture in the air it opens valve 11(or 11' in FIG. 3), to permit water to flow from tank 4 to outlet 10.The flow rate may be regulated in any one of several ways. Simple wayswould be to use a small valve or a partially closed valve at 11, or asmall opening at outlet 10 (or several small openings along a pipe atoutlet 10). However, small valves or small holes can become stuck orclogged and inoperative or erratic in performance. Inasmuch as a typicalmaximum flow rate for humidification is only about a gallon per hour,and sometimes far less, the problem of control is probably best met byuse of a simple low-cost periodic time switch 13. Periodically, if thehumidostat 12 calls for moisture, the time switch allows valve 11 to"open wide". During a relatively short period of time the water flowsrelatively fast and wets a fairly large area in the storage bin. Thenthe time switch turns the water off for a substantial period of time.The dampened rocks, concrete, and so on, yield up their moisture to theair flowing through the bin. As the humidity rises the humidostat closesthe valve, or keeps it from opening when the time switch turns on again.

If desired the humidostat may be eliminated and only a time switch usedto periodically open valve 11. Or, the time switch could be eliminated.

Heat transfer by heat-of-vaporization becomes important. As thecirculating air evaporates moisture from the bin it has a cooling or"refrigerating" effect and a substantial amount of heat is used fromstorage. And, that heat used from storage leaves the bin cooler. Coolwater is then pumped to the solar heat collector. Because the water iscooler it picks up more Btu's of free heat in the collector, that is,the solar heat collector becomes more efficient. (It is well-known thatany solar heat collector is more efficient in trapping solar energy atlow temperature levels.) So, heat transfer by heat-of-vaporization:

1. Increases efficiency of trapping and using free Solar Energy, therebyreducing fuel bills for auxiliary heat;

2. Makes the home air feel warmer;

3. Keeps the nose and throat, furniture, etc. from becoming dry.

In FIG. 4 use of hot flue gases through branch 28 reduces heat losses upthe chimney and thereby reduces use of auxiliary heat. Also, the furnacemay be eliminated and the domestic water heater used for auxiliary heatthrough hot water heat coil 33.

We claim:
 1. Heat storage bin apparatus and auxiliary heat apparatuscomprising heat storage material in an insulated compartment havingmeans to receive heat from an outside source and store it for use at alater time, combustion apparatus having a first flue pipe means fortransporting products of combustion to a point outside of said heatstorage bin, passing, in transit, in heat-exchange relationship withsaid storage bin to warm the air or other contents thereof at certaintimes, second flue pipe means to transport said products of combustionto a point outside of said heat storage bin substantially innon-heat-exchange relationship with said storage bin to avoid warmingthe air or other contents thereof during other periods of time, andmeans to direct the flue gasses through one of said flue pipes, orthrough the other.
 2. Apparatus as in claim 1 and means to circulate afluid through said storage bin apparatus for heating said fluid duringperiods of storage of heat in said storage bin by stored heat plus heatfrom said first-named flue pipe.